1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00

avcodec/sheervideo: Simplify creating VLC table

ff_init_vlc_from_lengths() can be used to offload the computation
of the codes; it also needn't check whether the codes are already
properly ordered (they are).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit is contained in:
Andreas Rheinhardt 2020-11-01 01:21:06 +01:00
parent f31bf4a1f9
commit d4a4a6747d

View File

@ -1784,11 +1784,10 @@ static void decode_rgb(AVCodecContext *avctx, AVFrame *p, GetBitContext *gb)
static av_cold int build_vlc(VLC *vlc, const SheerTable *table)
{
const uint8_t *cur = table->lens;
uint16_t codes[1024];
uint8_t lens[1024];
unsigned count = 0;
for (unsigned step = 1, len = 1, index = 0; len > 0; len += step) {
for (int step = 1, len = 1; len > 0; len += step) {
unsigned new_count = count;
if (len == 16) {
@ -1797,17 +1796,13 @@ static av_cold int build_vlc(VLC *vlc, const SheerTable *table)
} else
new_count += *cur++;
for (; count < new_count; count++) {
codes[count] = index >> (32 - len);
index += 1U << (32 - len);
for (; count < new_count; count++)
lens[count] = len;
}
}
ff_free_vlc(vlc);
return init_vlc(vlc, SHEER_VLC_BITS, count,
lens, sizeof(*lens), sizeof(*lens),
codes, sizeof(*codes), sizeof(*codes), 0);
return ff_init_vlc_from_lengths(vlc, SHEER_VLC_BITS, count,
lens, sizeof(*lens), NULL, 0, 0, 0, 0, NULL);
}
static int decode_frame(AVCodecContext *avctx,